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1 /*
2  * Copyright (C) 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
3  * Copyright (C) 2008 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  *
9  * 1.  Redistributions of source code must retain the above copyright
10  *     notice, this list of conditions and the following disclaimer.
11  * 2.  Redistributions in binary form must reproduce the above copyright
12  *     notice, this list of conditions and the following disclaimer in the
13  *     documentation and/or other materials provided with the distribution.
14  * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
15  *     its contributors may be used to endorse or promote products derived
16  *     from this software without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
19  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
20  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
21  * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
22  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
23  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
24  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
25  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28  */
29 
30 #include "config.h"
31 #include "MainResourceLoader.h"
32 
33 #include "ApplicationCacheHost.h"
34 #include "DOMWindow.h"
35 #include "Document.h"
36 #include "DocumentLoadTiming.h"
37 #include "DocumentLoader.h"
38 #include "FormState.h"
39 #include "Frame.h"
40 #include "FrameLoader.h"
41 #include "FrameLoaderClient.h"
42 #include "HTMLFormElement.h"
43 #include "InspectorInstrumentation.h"
44 #include "Page.h"
45 #if PLATFORM(QT)
46 #include "PluginDatabase.h"
47 #endif
48 #include "ResourceError.h"
49 #include "ResourceHandle.h"
50 #include "ResourceLoadScheduler.h"
51 #include "SchemeRegistry.h"
52 #include "Settings.h"
53 #include <wtf/CurrentTime.h>
54 
55 // FIXME: More that is in common with SubresourceLoader should move up into ResourceLoader.
56 
57 namespace WebCore {
58 
MainResourceLoader(Frame * frame)59 MainResourceLoader::MainResourceLoader(Frame* frame)
60     : ResourceLoader(frame, true, true)
61     , m_dataLoadTimer(this, &MainResourceLoader::handleDataLoadNow)
62     , m_loadingMultipartContent(false)
63     , m_waitingForContentPolicy(false)
64     , m_timeOfLastDataReceived(0.0)
65 {
66 }
67 
~MainResourceLoader()68 MainResourceLoader::~MainResourceLoader()
69 {
70 }
71 
create(Frame * frame)72 PassRefPtr<MainResourceLoader> MainResourceLoader::create(Frame* frame)
73 {
74     return adoptRef(new MainResourceLoader(frame));
75 }
76 
receivedError(const ResourceError & error)77 void MainResourceLoader::receivedError(const ResourceError& error)
78 {
79     // Calling receivedMainResourceError will likely result in the last reference to this object to go away.
80     RefPtr<MainResourceLoader> protect(this);
81     RefPtr<Frame> protectFrame(m_frame);
82 
83     // It is important that we call FrameLoader::receivedMainResourceError before calling
84     // FrameLoader::didFailToLoad because receivedMainResourceError clears out the relevant
85     // document loaders. Also, receivedMainResourceError ends up calling a FrameLoadDelegate method
86     // and didFailToLoad calls a ResourceLoadDelegate method and they need to be in the correct order.
87     frameLoader()->receivedMainResourceError(error, true);
88 
89     if (!cancelled()) {
90         ASSERT(!reachedTerminalState());
91         frameLoader()->notifier()->didFailToLoad(this, error);
92 
93         releaseResources();
94     }
95 
96     ASSERT(reachedTerminalState());
97 }
98 
didCancel(const ResourceError & error)99 void MainResourceLoader::didCancel(const ResourceError& error)
100 {
101     m_dataLoadTimer.stop();
102 
103     // Calling receivedMainResourceError will likely result in the last reference to this object to go away.
104     RefPtr<MainResourceLoader> protect(this);
105 
106     if (m_waitingForContentPolicy) {
107         frameLoader()->policyChecker()->cancelCheck();
108         ASSERT(m_waitingForContentPolicy);
109         m_waitingForContentPolicy = false;
110         deref(); // balances ref in didReceiveResponse
111     }
112     frameLoader()->receivedMainResourceError(error, true);
113     ResourceLoader::didCancel(error);
114 }
115 
interruptionForPolicyChangeError() const116 ResourceError MainResourceLoader::interruptionForPolicyChangeError() const
117 {
118     return frameLoader()->interruptionForPolicyChangeError(request());
119 }
120 
stopLoadingForPolicyChange()121 void MainResourceLoader::stopLoadingForPolicyChange()
122 {
123     ResourceError error = interruptionForPolicyChangeError();
124     error.setIsCancellation(true);
125     cancel(error);
126 }
127 
callContinueAfterNavigationPolicy(void * argument,const ResourceRequest & request,PassRefPtr<FormState>,bool shouldContinue)128 void MainResourceLoader::callContinueAfterNavigationPolicy(void* argument, const ResourceRequest& request, PassRefPtr<FormState>, bool shouldContinue)
129 {
130     static_cast<MainResourceLoader*>(argument)->continueAfterNavigationPolicy(request, shouldContinue);
131 }
132 
continueAfterNavigationPolicy(const ResourceRequest & request,bool shouldContinue)133 void MainResourceLoader::continueAfterNavigationPolicy(const ResourceRequest& request, bool shouldContinue)
134 {
135     if (!shouldContinue)
136         stopLoadingForPolicyChange();
137     else if (m_substituteData.isValid()) {
138         // A redirect resulted in loading substitute data.
139         ASSERT(documentLoader()->timing()->redirectCount);
140         handle()->cancel();
141         handleDataLoadSoon(request);
142     }
143 
144     deref(); // balances ref in willSendRequest
145 }
146 
isPostOrRedirectAfterPost(const ResourceRequest & newRequest,const ResourceResponse & redirectResponse)147 bool MainResourceLoader::isPostOrRedirectAfterPost(const ResourceRequest& newRequest, const ResourceResponse& redirectResponse)
148 {
149     if (newRequest.httpMethod() == "POST")
150         return true;
151 
152     int status = redirectResponse.httpStatusCode();
153     if (((status >= 301 && status <= 303) || status == 307)
154         && frameLoader()->initialRequest().httpMethod() == "POST")
155         return true;
156 
157     return false;
158 }
159 
addData(const char * data,int length,bool allAtOnce)160 void MainResourceLoader::addData(const char* data, int length, bool allAtOnce)
161 {
162     ResourceLoader::addData(data, length, allAtOnce);
163     documentLoader()->receivedData(data, length);
164 }
165 
willSendRequest(ResourceRequest & newRequest,const ResourceResponse & redirectResponse)166 void MainResourceLoader::willSendRequest(ResourceRequest& newRequest, const ResourceResponse& redirectResponse)
167 {
168     // Note that there are no asserts here as there are for the other callbacks. This is due to the
169     // fact that this "callback" is sent when starting every load, and the state of callback
170     // deferrals plays less of a part in this function in preventing the bad behavior deferring
171     // callbacks is meant to prevent.
172     ASSERT(!newRequest.isNull());
173 
174     // The additional processing can do anything including possibly removing the last
175     // reference to this object; one example of this is 3266216.
176     RefPtr<MainResourceLoader> protect(this);
177 
178     ASSERT(documentLoader()->timing()->fetchStart);
179     if (!redirectResponse.isNull()) {
180         DocumentLoadTiming* documentLoadTiming = documentLoader()->timing();
181 
182         // Check if the redirected url is allowed to access the redirecting url's timing information.
183         RefPtr<SecurityOrigin> securityOrigin = SecurityOrigin::create(newRequest.url());
184         if (!securityOrigin->canRequest(redirectResponse.url()))
185             documentLoadTiming->hasCrossOriginRedirect = true;
186 
187         documentLoadTiming->redirectCount++;
188         if (!documentLoadTiming->redirectStart)
189             documentLoadTiming->redirectStart = documentLoadTiming->fetchStart;
190         documentLoadTiming->redirectEnd = currentTime();
191         documentLoadTiming->fetchStart = documentLoadTiming->redirectEnd;
192     }
193 
194     // Update cookie policy base URL as URL changes, except for subframes, which use the
195     // URL of the main frame which doesn't change when we redirect.
196     if (frameLoader()->isLoadingMainFrame())
197         newRequest.setFirstPartyForCookies(newRequest.url());
198 
199     // If we're fielding a redirect in response to a POST, force a load from origin, since
200     // this is a common site technique to return to a page viewing some data that the POST
201     // just modified.
202     // Also, POST requests always load from origin, but this does not affect subresources.
203     if (newRequest.cachePolicy() == UseProtocolCachePolicy && isPostOrRedirectAfterPost(newRequest, redirectResponse))
204         newRequest.setCachePolicy(ReloadIgnoringCacheData);
205 
206     ResourceLoader::willSendRequest(newRequest, redirectResponse);
207 
208     // Don't set this on the first request. It is set when the main load was started.
209     m_documentLoader->setRequest(newRequest);
210 
211     Frame* top = m_frame->tree()->top();
212     if (top != m_frame)
213         frameLoader()->checkIfDisplayInsecureContent(top->document()->securityOrigin(), newRequest.url());
214 
215 #if ENABLE(OFFLINE_WEB_APPLICATIONS)
216     if (!redirectResponse.isNull()) {
217         // We checked application cache for initial URL, now we need to check it for redirected one.
218         ASSERT(!m_substituteData.isValid());
219         documentLoader()->applicationCacheHost()->maybeLoadMainResourceForRedirect(newRequest, m_substituteData);
220     }
221 #endif
222 
223     // FIXME: Ideally we'd stop the I/O until we hear back from the navigation policy delegate
224     // listener. But there's no way to do that in practice. So instead we cancel later if the
225     // listener tells us to. In practice that means the navigation policy needs to be decided
226     // synchronously for these redirect cases.
227     if (!redirectResponse.isNull()) {
228         ref(); // balanced by deref in continueAfterNavigationPolicy
229         frameLoader()->policyChecker()->checkNavigationPolicy(newRequest, callContinueAfterNavigationPolicy, this);
230     }
231 }
232 
shouldLoadAsEmptyDocument(const KURL & url)233 static bool shouldLoadAsEmptyDocument(const KURL& url)
234 {
235 #if PLATFORM(TORCHMOBILE)
236     return url.isEmpty() || (url.protocolIs("about") && equalIgnoringRef(url, blankURL()));
237 #else
238     return url.isEmpty() || SchemeRegistry::shouldLoadURLSchemeAsEmptyDocument(url.protocol());
239 #endif
240 }
241 
continueAfterContentPolicy(PolicyAction contentPolicy,const ResourceResponse & r)242 void MainResourceLoader::continueAfterContentPolicy(PolicyAction contentPolicy, const ResourceResponse& r)
243 {
244     KURL url = request().url();
245     const String& mimeType = r.mimeType();
246 
247     switch (contentPolicy) {
248     case PolicyUse: {
249         // Prevent remote web archives from loading because they can claim to be from any domain and thus avoid cross-domain security checks (4120255).
250         bool isRemoteWebArchive = equalIgnoringCase("application/x-webarchive", mimeType) && !m_substituteData.isValid() && !url.isLocalFile();
251         if (!frameLoader()->canShowMIMEType(mimeType) || isRemoteWebArchive) {
252             frameLoader()->policyChecker()->cannotShowMIMEType(r);
253             // Check reachedTerminalState since the load may have already been cancelled inside of _handleUnimplementablePolicyWithErrorCode::.
254             if (!reachedTerminalState())
255                 stopLoadingForPolicyChange();
256             return;
257         }
258         break;
259     }
260 
261     case PolicyDownload:
262         // m_handle can be null, e.g. when loading a substitute resource from application cache.
263         if (!m_handle) {
264             receivedError(cannotShowURLError());
265             return;
266         }
267         InspectorInstrumentation::continueWithPolicyDownload(m_frame.get(), documentLoader(), identifier(), r);
268         frameLoader()->client()->download(m_handle.get(), request(), m_handle.get()->firstRequest(), r);
269         // It might have gone missing
270         if (frameLoader())
271             receivedError(interruptionForPolicyChangeError());
272         return;
273 
274     case PolicyIgnore:
275         InspectorInstrumentation::continueWithPolicyIgnore(m_frame.get(), documentLoader(), identifier(), r);
276         stopLoadingForPolicyChange();
277         return;
278 
279     default:
280         ASSERT_NOT_REACHED();
281     }
282 
283     RefPtr<MainResourceLoader> protect(this);
284 
285     if (r.isHTTP()) {
286         int status = r.httpStatusCode();
287         if (status < 200 || status >= 300) {
288             bool hostedByObject = frameLoader()->isHostedByObjectElement();
289 
290             frameLoader()->handleFallbackContent();
291             // object elements are no longer rendered after we fallback, so don't
292             // keep trying to process data from their load
293 
294             if (hostedByObject)
295                 cancel();
296         }
297     }
298 
299     // we may have cancelled this load as part of switching to fallback content
300     if (!reachedTerminalState())
301         ResourceLoader::didReceiveResponse(r);
302 
303     if (frameLoader() && !frameLoader()->isStopping()) {
304         if (m_substituteData.isValid()) {
305             if (m_substituteData.content()->size())
306                 didReceiveData(m_substituteData.content()->data(), m_substituteData.content()->size(), m_substituteData.content()->size(), true);
307             if (frameLoader() && !frameLoader()->isStopping())
308                 didFinishLoading(0);
309         } else if (shouldLoadAsEmptyDocument(url) || frameLoader()->representationExistsForURLScheme(url.protocol()))
310             didFinishLoading(0);
311     }
312 }
313 
callContinueAfterContentPolicy(void * argument,PolicyAction policy)314 void MainResourceLoader::callContinueAfterContentPolicy(void* argument, PolicyAction policy)
315 {
316     static_cast<MainResourceLoader*>(argument)->continueAfterContentPolicy(policy);
317 }
318 
continueAfterContentPolicy(PolicyAction policy)319 void MainResourceLoader::continueAfterContentPolicy(PolicyAction policy)
320 {
321     ASSERT(m_waitingForContentPolicy);
322     m_waitingForContentPolicy = false;
323     if (frameLoader() && !frameLoader()->isStopping())
324         continueAfterContentPolicy(policy, m_response);
325     deref(); // balances ref in didReceiveResponse
326 }
327 
328 #if PLATFORM(QT)
substituteMIMETypeFromPluginDatabase(const ResourceResponse & r)329 void MainResourceLoader::substituteMIMETypeFromPluginDatabase(const ResourceResponse& r)
330 {
331     if (!m_frame->loader()->subframeLoader()->allowPlugins(NotAboutToInstantiatePlugin))
332         return;
333 
334     String filename = r.url().lastPathComponent();
335     if (filename.endsWith("/"))
336         return;
337 
338     size_t extensionPos = filename.reverseFind('.');
339     if (extensionPos == notFound)
340         return;
341 
342     String extension = filename.substring(extensionPos + 1);
343     String mimeType = PluginDatabase::installedPlugins()->MIMETypeForExtension(extension);
344     if (!mimeType.isEmpty()) {
345         ResourceResponse* response = const_cast<ResourceResponse*>(&r);
346         response->setMimeType(mimeType);
347     }
348 }
349 #endif
350 
didReceiveResponse(const ResourceResponse & r)351 void MainResourceLoader::didReceiveResponse(const ResourceResponse& r)
352 {
353 #if ENABLE(OFFLINE_WEB_APPLICATIONS)
354     if (documentLoader()->applicationCacheHost()->maybeLoadFallbackForMainResponse(request(), r))
355         return;
356 #endif
357 
358     HTTPHeaderMap::const_iterator it = r.httpHeaderFields().find(AtomicString("x-frame-options"));
359     if (it != r.httpHeaderFields().end()) {
360         String content = it->second;
361         if (m_frame->loader()->shouldInterruptLoadForXFrameOptions(content, r.url())) {
362             InspectorInstrumentation::continueAfterXFrameOptionsDenied(m_frame.get(), documentLoader(), identifier(), r);
363             DEFINE_STATIC_LOCAL(String, consoleMessage, ("Refused to display document because display forbidden by X-Frame-Options.\n"));
364             m_frame->domWindow()->console()->addMessage(JSMessageSource, LogMessageType, ErrorMessageLevel, consoleMessage, 1, String());
365 
366             cancel();
367             return;
368         }
369     }
370 
371     // There is a bug in CFNetwork where callbacks can be dispatched even when loads are deferred.
372     // See <rdar://problem/6304600> for more details.
373 #if !USE(CF)
374     ASSERT(shouldLoadAsEmptyDocument(r.url()) || !defersLoading());
375 #endif
376 
377 #if PLATFORM(QT)
378     if (r.mimeType() == "application/octet-stream")
379         substituteMIMETypeFromPluginDatabase(r);
380 #endif
381 
382     if (m_loadingMultipartContent) {
383         frameLoader()->setupForReplaceByMIMEType(r.mimeType());
384         clearResourceData();
385     }
386 
387     if (r.isMultipart())
388         m_loadingMultipartContent = true;
389 
390     // The additional processing can do anything including possibly removing the last
391     // reference to this object; one example of this is 3266216.
392     RefPtr<MainResourceLoader> protect(this);
393 
394     m_documentLoader->setResponse(r);
395 
396     m_response = r;
397 
398     ASSERT(!m_waitingForContentPolicy);
399     m_waitingForContentPolicy = true;
400     ref(); // balanced by deref in continueAfterContentPolicy and didCancel
401 
402     ASSERT(frameLoader()->activeDocumentLoader());
403 
404     // Always show content with valid substitute data.
405     if (frameLoader()->activeDocumentLoader()->substituteData().isValid()) {
406         callContinueAfterContentPolicy(this, PolicyUse);
407         return;
408     }
409 
410 #if ENABLE(FTPDIR)
411     // Respect the hidden FTP Directory Listing pref so it can be tested even if the policy delegate might otherwise disallow it
412     Settings* settings = m_frame->settings();
413     if (settings && settings->forceFTPDirectoryListings() && m_response.mimeType() == "application/x-ftp-directory") {
414         callContinueAfterContentPolicy(this, PolicyUse);
415         return;
416     }
417 #endif
418 
419     frameLoader()->policyChecker()->checkContentPolicy(m_response, callContinueAfterContentPolicy, this);
420 }
421 
didReceiveData(const char * data,int length,long long encodedDataLength,bool allAtOnce)422 void MainResourceLoader::didReceiveData(const char* data, int length, long long encodedDataLength, bool allAtOnce)
423 {
424     ASSERT(data);
425     ASSERT(length != 0);
426 
427     ASSERT(!m_response.isNull());
428 
429 #if USE(CFNETWORK) || (PLATFORM(MAC) && !defined(BUILDING_ON_TIGER))
430     // Workaround for <rdar://problem/6060782>
431     if (m_response.isNull()) {
432         m_response = ResourceResponse(KURL(), "text/html", 0, String(), String());
433         if (DocumentLoader* documentLoader = frameLoader()->activeDocumentLoader())
434             documentLoader->setResponse(m_response);
435     }
436 #endif
437 
438     // There is a bug in CFNetwork where callbacks can be dispatched even when loads are deferred.
439     // See <rdar://problem/6304600> for more details.
440 #if !USE(CF)
441     ASSERT(!defersLoading());
442 #endif
443 
444  #if ENABLE(OFFLINE_WEB_APPLICATIONS)
445     documentLoader()->applicationCacheHost()->mainResourceDataReceived(data, length, encodedDataLength, allAtOnce);
446 #endif
447 
448     // The additional processing can do anything including possibly removing the last
449     // reference to this object; one example of this is 3266216.
450     RefPtr<MainResourceLoader> protect(this);
451 
452     m_timeOfLastDataReceived = currentTime();
453 
454     ResourceLoader::didReceiveData(data, length, encodedDataLength, allAtOnce);
455 }
456 
didFinishLoading(double finishTime)457 void MainResourceLoader::didFinishLoading(double finishTime)
458 {
459     // There is a bug in CFNetwork where callbacks can be dispatched even when loads are deferred.
460     // See <rdar://problem/6304600> for more details.
461 #if !USE(CF)
462     ASSERT(shouldLoadAsEmptyDocument(frameLoader()->activeDocumentLoader()->url()) || !defersLoading());
463 #endif
464 
465     // The additional processing can do anything including possibly removing the last
466     // reference to this object.
467     RefPtr<MainResourceLoader> protect(this);
468 
469 #if ENABLE(OFFLINE_WEB_APPLICATIONS)
470     RefPtr<DocumentLoader> dl = documentLoader();
471 #endif
472 
473     ASSERT(!documentLoader()->timing()->responseEnd);
474     documentLoader()->timing()->responseEnd = finishTime ? finishTime : (m_timeOfLastDataReceived ? m_timeOfLastDataReceived : currentTime());
475     frameLoader()->finishedLoading();
476     ResourceLoader::didFinishLoading(finishTime);
477 
478 #if ENABLE(OFFLINE_WEB_APPLICATIONS)
479     dl->applicationCacheHost()->finishedLoadingMainResource();
480 #endif
481 }
482 
didFail(const ResourceError & error)483 void MainResourceLoader::didFail(const ResourceError& error)
484 {
485 #if ENABLE(OFFLINE_WEB_APPLICATIONS)
486     if (documentLoader()->applicationCacheHost()->maybeLoadFallbackForMainError(request(), error))
487         return;
488 #endif
489 
490     // There is a bug in CFNetwork where callbacks can be dispatched even when loads are deferred.
491     // See <rdar://problem/6304600> for more details.
492 #if !USE(CF)
493     ASSERT(!defersLoading());
494 #endif
495 
496     receivedError(error);
497 }
498 
handleEmptyLoad(const KURL & url,bool forURLScheme)499 void MainResourceLoader::handleEmptyLoad(const KURL& url, bool forURLScheme)
500 {
501     String mimeType;
502     if (forURLScheme)
503         mimeType = frameLoader()->generatedMIMETypeForURLScheme(url.protocol());
504     else
505         mimeType = "text/html";
506 
507     ResourceResponse response(url, mimeType, 0, String(), String());
508     didReceiveResponse(response);
509 }
510 
handleDataLoadNow(MainResourceLoaderTimer *)511 void MainResourceLoader::handleDataLoadNow(MainResourceLoaderTimer*)
512 {
513     RefPtr<MainResourceLoader> protect(this);
514 
515     KURL url = m_substituteData.responseURL();
516     if (url.isEmpty())
517         url = m_initialRequest.url();
518 
519     // Clear the initial request here so that subsequent entries into the
520     // loader will not think there's still a deferred load left to do.
521     m_initialRequest = ResourceRequest();
522 
523     ResourceResponse response(url, m_substituteData.mimeType(), m_substituteData.content()->size(), m_substituteData.textEncoding(), "");
524     didReceiveResponse(response);
525 }
526 
startDataLoadTimer()527 void MainResourceLoader::startDataLoadTimer()
528 {
529     m_dataLoadTimer.startOneShot(0);
530 
531 #if HAVE(RUNLOOP_TIMER)
532     if (SchedulePairHashSet* scheduledPairs = m_frame->page()->scheduledRunLoopPairs())
533         m_dataLoadTimer.schedule(*scheduledPairs);
534 #endif
535 }
536 
handleDataLoadSoon(const ResourceRequest & r)537 void MainResourceLoader::handleDataLoadSoon(const ResourceRequest& r)
538 {
539     m_initialRequest = r;
540 
541     if (m_documentLoader->deferMainResourceDataLoad())
542         startDataLoadTimer();
543     else
544         handleDataLoadNow(0);
545 }
546 
loadNow(ResourceRequest & r)547 bool MainResourceLoader::loadNow(ResourceRequest& r)
548 {
549     bool shouldLoadEmptyBeforeRedirect = shouldLoadAsEmptyDocument(r.url());
550 
551     ASSERT(!m_handle);
552     ASSERT(shouldLoadEmptyBeforeRedirect || !defersLoading());
553 
554     // Send this synthetic delegate callback since clients expect it, and
555     // we no longer send the callback from within NSURLConnection for
556     // initial requests.
557     willSendRequest(r, ResourceResponse());
558 
559     // <rdar://problem/4801066>
560     // willSendRequest() is liable to make the call to frameLoader() return NULL, so we need to check that here
561     if (!frameLoader())
562         return false;
563 
564     const KURL& url = r.url();
565     bool shouldLoadEmpty = shouldLoadAsEmptyDocument(url) && !m_substituteData.isValid();
566 
567     if (shouldLoadEmptyBeforeRedirect && !shouldLoadEmpty && defersLoading())
568         return true;
569 
570     resourceLoadScheduler()->addMainResourceLoad(this);
571     if (m_substituteData.isValid())
572         handleDataLoadSoon(r);
573     else if (shouldLoadEmpty || frameLoader()->representationExistsForURLScheme(url.protocol()))
574         handleEmptyLoad(url, !shouldLoadEmpty);
575     else
576         m_handle = ResourceHandle::create(m_frame->loader()->networkingContext(), r, this, false, true);
577 
578     return false;
579 }
580 
load(const ResourceRequest & r,const SubstituteData & substituteData)581 bool MainResourceLoader::load(const ResourceRequest& r, const SubstituteData& substituteData)
582 {
583     ASSERT(!m_handle);
584 
585     m_substituteData = substituteData;
586 
587     ASSERT(documentLoader()->timing()->navigationStart);
588     ASSERT(!documentLoader()->timing()->fetchStart);
589     documentLoader()->timing()->fetchStart = currentTime();
590     ResourceRequest request(r);
591 
592 #if ENABLE(OFFLINE_WEB_APPLICATIONS)
593     documentLoader()->applicationCacheHost()->maybeLoadMainResource(request, m_substituteData);
594 #endif
595 
596     bool defer = defersLoading();
597     if (defer) {
598         bool shouldLoadEmpty = shouldLoadAsEmptyDocument(request.url());
599         if (shouldLoadEmpty)
600             defer = false;
601     }
602     if (!defer) {
603         if (loadNow(request)) {
604             // Started as an empty document, but was redirected to something non-empty.
605             ASSERT(defersLoading());
606             defer = true;
607         }
608     }
609     if (defer)
610         m_initialRequest = request;
611 
612     return true;
613 }
614 
setDefersLoading(bool defers)615 void MainResourceLoader::setDefersLoading(bool defers)
616 {
617     ResourceLoader::setDefersLoading(defers);
618 
619     if (defers) {
620         if (m_dataLoadTimer.isActive())
621             m_dataLoadTimer.stop();
622     } else {
623         if (m_initialRequest.isNull())
624             return;
625 
626         if (m_substituteData.isValid() && m_documentLoader->deferMainResourceDataLoad())
627             startDataLoadTimer();
628         else {
629             ResourceRequest r(m_initialRequest);
630             m_initialRequest = ResourceRequest();
631             loadNow(r);
632         }
633     }
634 }
635 
636 }
637